支持概念设计的分布式协同设计环境的研究

一个复杂产品的概念设计往往需要多学科领域专家之间的协同。基于黑板模型 ,本文提出了一个分布式模块化协同设计框架结构。首先分别介绍了支持该框架结构的几个关键技术 ,即产品信息共享模型、设计问题的分布式构模方法以及基于约束的冲突检测方法。然后利用这些框架支持技术以及网络使能技术开发了一个分布式模块化协同设计环境 DCMDE,能有效地支持不同地理位置、不同学科的设计人员进行机械产品的协同概念设计。一个齿轮箱协同方案设计实例显示了系统的有效性     

MULTI AGENT COLLABORATIVE DESIGN SYSTEM MODEL BASED ON THE INTERNET AND EXPERIMENTS

0 INTRODUCTIONDstributed Artificial Intelligence(DAI ) is one ofthe imPOrtant branches of artificial intelligence. In thedomain of artificial intelligence, agent is used torepresent the object with some intelligence andautonomous decision-making function so as todistinguish it from common object.The agent isusually called" Autonomous Object" .A distributedartificial intelligence consists of many agents. Typicalstructure of an 8gent includes the partial knowledgebase, inference and dec…     

Design justification of manufacturing systems—a review

The development of design systems which ensure economic feasibility has been the focus of recent research in the manufacturing area. Traditional design and justification approaches have been cited as having shortcomings; thus, there have been a variety of modifications and enhancements developed. An approach that is conceptually different from the traditional approaches seeks the integration of the economic analysis within the design process. We denote this approach as thedesign justification method. This paper reviews literature related to the explicit and implicit integration of economic factors in the manufacturing system design process, followed by supporting issues for the implementation of the design justification concept.     

A graph and matrix representation scheme for functional design of mechanical products

This paper presents a graph and matrix representation scheme for the functional design of mechanical products, which provides a good basis to generate an explicit and comprehensive functional model used for functional reasoning. Three key features of the scheme are (1) The representation of the causal way behaviors are interconnected; (2) The representation of two types of functional relations: decomposed into and supported by; and (3) Support for diverse functional reasoning paths: three alternative B-FES/e paths are currently available. The scheme can guide functional design of mechanical products through functional reasoning steps including functional supportive synthesis, causal behavioral reasoning and functional decomposition. The developed functional model and its representation applied in a knowledge-based design environment can speed up the functional design process by automating functional reasoning steps. The proposed approach has been evaluated with a functional design example of a terminal cutoff unit in an automatic assembly system for manufacturing electronic connectors.     

A Distributive and Collaborative Concurrent Product Design System through the WWW/Internet

Concurrent engineering involves the integration of people, tools, information, and processes into a responsive and efficient system. This paper addresses a key requirement in distributed concurrent engineering, namely, the ability for geographically dispersed and disparate parties, having heterogeneous computing platforms, to exchange design and manufacturing data. The development of an effective and efficient collaborative product design support environment based on the WWW/Internet is presented. A new method that reduces the transmission time through the use of macro files is proposed to realise the real-time communication, together with a monitoring methodology for synchronising group operations, and maintaining consistency of shared CAD models in a cooperative design review (co-modifying) process. Based on the proposed methods, a software interface has been developed to extend the traditional single location CAD software system to a multi-location application for coordinated product design through the Internet. This software interface was coded in Java. The architecture is a connection-oriented client/server structure using TCP/IP protocol. Unigraphics on a UNIX Workstation and MicroStation on Windows NT have been successfully integrated. The findings of this paper allow product designers to exchange and share product data, communicate with team members, modify geometry data on particular aspects of the design, and maintain operations consistency in all the distributed cooperative sites on a wide variety of platforms.     

基于服务器组的分布式MSCAD系统

在MS-CAD研究中,如何将分立于不同领域的CAD功能模块连接起来,在系统级进行设计、模拟、仿真是一个关键问题.Internet的广泛应用与分布式处理技术的日益成熟为解决这个问题提供了新的思路.本文提出了一个基于服务器组的分布式CAD新方案,采用该方案所设计的CAD系统可在系统级对微系统进行辅助设计和模拟仿真,具有较高的智能以及良好的开放性和可扩展性.     

基于J2EE的分布式项目管理系统应用研究

随着网络技术的发展和企业信息化的深入，出现了以“项目”为驱动而产生的虚拟企业，使得原有的企业组织结构与运营方式发生了新的变化；项目管理在企业中的应用出现了新的特点。本文结合J2EE(Java 2 Enterprise Edition)在计算机应用系统开发中的优势，构建了基于。J2EE的分布式项目管理系统，并对系统中各模块的功能设计进行了描述。     

Simulation Analysis of a PCB Factory using Factorial Design – A Case Study

This study describes simulation modelling and analysis of a serial production line in a printed circuit board (PCB) factory. Simulation technique is applied to evaluate the performance of the existing manufacturing system, which requires modification to achieve two conflicting objectives, i.e. to maximise the average throughput rate and to minimise the average lead time. Based on a full factorial design, the computer model, which is developed using SIMFACTORY, has been used for finding out the active factors that have a great impact on the current operational problems. Then, a new system design is proposed to enhance the overall performance and is verified using a simulation model. The simulation approach presented here is also applicable to a wide variety of complex operational problems. ID="A1"Correspondance and offprint requests to: Dr F.T.S.Chan, Department of Industrial and Manufacturing Systems Engineering, University of Hong Kong, Pokfulam Road, Hong Kong. E-mail: ftschan@hkucc.hku.hk     

A distributed image-based virtual prototyping system with novel rendering tactics

Taking automobile design as a study case, this paper presents the approaches to implement a distributed image-based virtual prototyping (VP) system employing distributed virtual reality (DVR) technology combined with image-based rendering (IBR) technology. Firstly, the methods to implement an image-based closed spherical space are presented, which can be used to construct a photo-quality virtual prototype; secondly, the novel vision sensitivity-based rendering tactic and the relevant image cubic-spline interpolation methods, which visibly improve the efficiency of rendering, is represented. Finally, a distributed image-based virtual prototyping system is implemented, by which a product designer can easily and rapidly construct a photo-quality virtual prototype and distribute it on the Internet, whereby buyers can visually understand whether or not the product can meet their individual requirements. This system enables buyers and designers to visually evaluate and discuss the design remotely, which has consequently improved the design efficiency greatly and lowered the cost substantially.     

分布环境下面向装配的产品协同设计集成平台

为提高异地设计时产品的可装配性设计质量,提出了分布环境下面向装配的产品协同设计方法,从零件设计、产品结构预装配和产品过程预装配3个方面论述了可装配性设计内容,建立并实现了支持网络环境下面向装配的产品协同设计集成平台,详细描述了平台的功能模块,并通过涡轮膨胀机实例说明了异地人员间利用该平台实施面向装配的协同设计过程。     

An agent- and service-based collaborative design architecture under a dynamic integration environment

The shortening of product realization times and the increase of product complication require multidisciplinary experts to cooperate dynamically and closely in the whole product development lifecycle, behavior that has been previously unfamiliar. To further improve the design cooperation efficiency under this environment, this paper presents a novel cooperative design architecture using revolutionary Internet, agent, and semantic Web technologies. Based on the concept of service provision, intelligent Web-agent groups act as the function backbone to organize the service-based running of the system. Multidisciplinary product development units can be dynamically formed and configured in a knowledge-integration perspective. The layer-based architecture encapsulates distributed knowledge at a higher abstract level and coordinates lifecycle activities from different domains. Semantic-rich service expression and intelligent service accessing through agent mediation make the system more flexible. Within this dynamic cooperative environment, all of the participants involved and their distributed knowledge can be integrated as a whole to achieve more efficient and more intelligent design cooperation.     

Design and implementation of an Internet based effective controlling and monitoring system with wireless fieldbus communications technologies for process automation--an experimental study

The network requirements of control systems in industrial applications increase day by day. The Internet based control system and various fieldbus systems have been designed in order to meet these requirements. This paper describes an Internet based control system with wireless fieldbus communication designed for distributed processes. The system was implemented as an experimental setup in a laboratory. In industrial facilities, the process control layer and the distance connection of the distributed control devices in the lowest levels of the industrial production environment are provided with fieldbus networks. In this paper, the Internet based control system that will be able to meet the system requirements with a new-generation communication structure, which is called wired/wireless hybrid system, has been designed on field level and carried out to cover all sectors of distributed automation, from process control, to distributed input/output (I/O). The system has been accomplished by hardware structure with a programmable logic controller (PLC), a communication processor (CP) module, two industrial wireless modules and a distributed I/O module, Motor Protection Package (MPP) and software structure with WinCC flexible program used for the screen of Scada (Supervisory Control And Data Acquisition), SIMATIC MANAGER package program ("STEP7") used for the hardware and network configuration and also for downloading control program to PLC.     

A Case-Based Design System for the Conceptual Design of Electrical Connectors

The paper describes a case-based system for the conceptual design of connectors. The objective is to increase the designer productivity by providing case-based support for automatic exploration of the design alternatives that can be generated from past design cases. A framework for case-representation and library structure is developed based on analysis of the connector design process. The case-based design approach takes advantage of the distinct subcomponents in a connector to retrieve past connector designs based on the concepts of the desired subcomponents. An industrial example is given to illustrate the generation of the conceptual design alternatives by combining the retrieved connector designs with respect to their subcomponents. The proposed system allows the designer to select the appropriate alternative or it can recommend alternatives based on the complexity of the combination. The selected alternative would be modified further in the detailed design stage to develop the complete design. Although this paper provides an approach to automating the conceptual design of connectors, the approach could be useful to other products that contain distinct subcomponents confined within a fixed topology. ID="A1"Correspondance and offprint requests to S. C. Fok, School of Mechanical and Production Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798. E-mail: mscfok@ntu.edu.sg:     

A case-based reasoning approach to generating new product ideas

This paper presents an approach to facilitate the generation of new product ideas. In this approach, a product is represented by a vector, which involves a number of product attributes. These attributes are defined based on the user-centered design (UCD) paradigm. That is, the context of use and interactions with users for the product is described by these attributes. By the product representation, a product database can be established. For a benchmarking product, we use the case-based reasoning (CBR) technique to retrieve those products, which are “sufficiently relevant” to the benchmarking one, from the database. The functions of the retrieved products are the candidate new ideas to be added on the benchmarking product. These retrieved products are screened manually to identify creative and valuable ideas. A prototype system of this approach has been implemented. Experiments show that the proposed approach outperforms the brainstorming technique, which has been widely used in industry.     

A Hybrid Intelligent Systems Approach for Die Design in Sheet Metal Forming

Die design is heavily experience based and the die design process is an iterative procedure of trial and error in order to obtain a final die design for the successful manufacture of stampings. Most automotive industries use internal guidelines and past experience for die design. Even though powerful computer-aided design systems are being used in automotive industry, the lack of adequate analysis tools at the initial die geometry design stage hinders the die manufacturing process, and also necessitates lead times of the order of 5–30 weeks [1]. At the concept design stage, and during the initial die development process, the variations in geometry and process conditions are so large that it is prohibitively expensive to use 3D finite element analysis. The complexity of die design heuristic knowledge hinders the development and application of knowledge-based systems. Hybrid intelligent systems are computer programs in which at least one of the constituent models simulates intelligent behaviour [2]. These models could be knowledge-based systems, artificial neural networks, fuzzy logic systems, etc. In this approach both artificial neural networks, knowledge-based systems and finite-element analysis (FEA) for modelling the design process are used. A simulation-based design approach [3] for the die design process is followed. Artificial neural networks (ANNs) are preliminary design tools which indicate the formability of the component geometry, for the selected process and material conditions. The ANN module is trained from FEA results for a generic set of component geometries, process conditions, and material properties. The final die design validation is carried out by FEA. The intelligent frame-work incorporates rules for material selection, process parameter selection and their modification. Component geometry is a critical parameter which affects the manufacturability of the given part. Hence, an intelligent geometry handling module, which automatically modifies and optimises the geometry of the designed die, is implemented in the present system. Knowledge-based blackboard architecture is used for the integration of various analysis models such as CAD, FEA, and ANN, as an intelligent framework for die design [4]. The hybrid intelligent system provides an integrated decision support environment for simulation and analysis of the forming process, both during the initial die design phase and during the die tryout phase. The hybrid intelligent systems approach supports the capability for automatic evaluation of prospective die design for manufacturability, and performs automatic modification of design inputs. Applications of the hybrid intelligent system for die design are described together with a comparison with shop floor data.     

Internet-Based Collaboration System: Press-Die Design Process for Automobile Manufacturer

To survive in a severe competitive environment, manufacturing enterprises must accomplish objectives such as cost reduction, quality improvement and short time-to-market. Also, as the manufacturing environment becomes more globalised and distributed, it is important to manage the workflow harmoniously and to share the information efficiently among geographically dispersed users. In this research, we propose a collaborative design and engineering system, which manages various design processes in an integrated manner and enables the sharing of design information. Because design information is usually very large in its size, it is very difficult to synchronise the individual design data of each designer with the entire design data. As a solution for efficient data sharing among the designers in networks, CORBA can be applied to synchronise the states of the design information. If one user modifies design data on his/her computer, this operation is detected and transmitted to other users who are related with the design modification. A receiver’s computer automatically synchronises its data with the sender’s message. In this paper, an Internet-based collaboration system for a press-die design process for automobile manufacturers is developed with CORBA, Java, Java3D and a relational database system. After modelling a practical press-die design process with the UML language, workflow routing paths are created by the modelling data. Cost and time for design can be estimated by the concurrent quasi-procedural method. The system developed can notify design modification to users when it is required, and enables users to share design models and analysis results. Designers can exchange opinions about common design matters by the conferencing function of the system. ID="A1" Correspondence and offprint requests to: S. H. Kong, Automatic Control Research Centre, Seoul National University, San 56–1, Shin-lim-dong, Kwanak-ku, Seoul 151–742, Korea. E-mail: silkysix@snu-.ac.kr     

基于Internet/Intranet的机械产品设计资源共享系统研究

分析了基于Internet／Intranet的设计现状，讨论了基于浏览器／服务器模式的机械产品设计资源共享系统的特点，提出了基于Internet／Intranet的机械产品设计资源共享系统模型。在此基础上设计开发了基于Internet／Intranet的齿轮传动参数化设计系统。     

模型驱动复杂机电系统软件与物理并行概念设计

并行设计是机电一体化系统概念设计的重要发展趋势,而软件作为复杂机电系统的重要组成部分,其早期设计通常与物理子系统串行开展,这极大限制了软件设计空间并导致严重的早期设计缺陷。为在复杂机电系统概念设计阶段实现软件与物理子系统的并行设计,提出了一种基于SysML的模型驱动软件与物理并行概念设计方法。将基于流的物理功能表示与基于数据/控制流图的软件功能表示相结合,提出了基于SysML的混合功能模型,通过该模型驱动软件与物理子系统设计的并行开展。在物理设计方面,基于功能效应匹配及时序规则模板实现带隐含时序约束的工作原理检索与筛选;在软件设计方面,基于分布式控制应用设计模式提出软件组件及其行为模型自动生成方法。最后,以移动机器人系统为例,展示了复杂机电系统软件与物理并行概念设计过程。     

Conceptual Design Using Evolution Strategy

Conceptual design is one of the most important activities in new product development. Inappropriate design concepts could result in high redesign cost and delay in product realisation. The generation of conceptual designs is a time-consuming and mentally exhausting process. It involves combining design features to generate as many potential design concepts as possible. As not all features combinations are feasible, decision-makers have to narrow down the potential solutions and subsequently select appropriate concept(s) for further development. This work concerns the automation of the conceptual design process using an evolutionary strategy. The paper proposes a design attribute encapsulation method, which is applied to the chromosome representation of the design concept, to facilitate the search for a promising combination of features. The design of golf clubs for children is used to illustrate the application of the proposed approach. Mathematical analysis shows that with the proposed approach, the probability of generating a feasible concept during the mutation and crossover is higher with better use of the feasibility rules. ID="A1" Correspondence and offprint requests to: S. C. Fok, School of Mechanical and Production Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798. E-mail: mscfok@ntu.edu.sg     

网上通用产品配置设计工具的研究

主要介绍一种新的网上通用产品配置设计工具。用户可以利用该工具直接在网上建立和维护自己企业定制的产品配置设计系统，而不需要进行专门的编程。网上的产品配置设计系统包括按功能的产品配置设计和按结构的产品配置设计，一般用户可以在该系统上进行各种产品的配置设计。该工具能有效地支持企业利用因特网进行大批量定制生产。